PARENT SESSION
SLIDE SESSION 21: FOLLICLE DEVELOPMENT: INPUTS TO FUNCTIONAL MATURATION
Chairs: Jeff May, Jerry Menon, Kari Doyle (Trainee)
Univ Ottawa-Lamoureaux 122
1:30 PM-3:30 PM

HORMONAL REGULATION OF ADAMTS-1 IN THE RODENT OVARY.

Doyle, Kari¹, Russell, Darryl ¹, Richards, JoAnne¹, ¹

ABSTRACT- The purpose of this study is to define the molecular mechanisms by which hormones [luteininzing hormone (LH) and progesterone] regulate the expression of a novel multifunctional protease, ADAMTS-1 (A Disintegrin And Metalloproteinase with Thrombospondin-like motifs) in the ovary. In previous studies we have shown that the progesterone receptor (PR) and ADAMTS-1 are induced selectively in granulosa cells of preovulatory follicles by the ovulatory surge of LH. Both PR and ADAMTS-1 mRNA and protein are absent in preovulatory follicles of the PR knockout (PRKO) mice that fail to ovulate. To analyze the direct effects of LH and PR on the expression of ADAMTS-1, rat granulosa cells were isolated and cultured in the presence of various agonists that mimic the actions of LH [forskolin (Fo) and the phorbol ester, PMA]. Agonists (R5020) and antagonists (ZK98299) of PR were also used in this system. By semi-quantitative RT-PCR we show that Fo+PMA induces ADAMTS-1 and PR mRNA expression above controls. Neither R5020 nor ZK98299 alone or in combination with Fo+PMA altered the expression of PR or ADAMTS-1. Thus, LH, but not progesterone, activated pathways induce expression of ADAMTS-1 in cultured granulosa cells. To test the effects of the agonists and antagonists more directly on the transactivation of the ADAMTS-1 gene, ADAMTS-1 luciferase reporter constructs were made and transfected into primary granulosa cell cultures. Fo+PMA treatment of cells stimulated transactivation of constructs, and ZK98299 had no effect. To determine if PR is required for the response to Fo+PMA by interacting with other transcription factors, similar studies were done using PRKO mouse granulosa cells. ADAMTS-1 was induced by Fo+PMA in PRKO granulosa cells, ruling out the possibilty that PR is interacting with other transcription factors. These data indicate that PR may act in a novel way by impacting specific kinase cascades, that in turn may activate the transcription of ADAMTS-1.

KEY WORDS: ADAMTS-1, Progesterone Receptor, Ovulation